Printing element attaching device



L. M. STEM PEL PRINTING ELEMENT ATTACHING DEVICE Oct. 30, 1945.

File Nov. 24, 1942 IN VEN TOR. Laszlom Jrempe/ AT TOR/YE Y5 Patented Oct. 30, 1945 UNITED STATES PATENT ()FFICE PRINTING ELEMENT ATTAGHI-NG DEVICE Easzlo M. Stempel; Coraopolis, Pa,., assignor to The Lithograph Press Manufacturing Company; Pittsburgh, Pa., a corporation of Pennsylvania Application November 24, 1342, Serial No. 466,714

9' Glaims.

This invention relatesto. atransfer cylinder-tor applying, a printed or lithographed. impression. to a. web of paper or other material to: be printed. Such. cylinders are. used in. lithog p and printing presses, and. especially in presses. of the type known as ofisetpressesinwhich the. rubber transfer cylinder blanket bears against a cylindrical printing. plate mounted on a plate; cylinder disposed parallel with the transfer cylinder, as shown in Smith. Patent No.\l,949',132 issued Feb. 21', 1934, on which this. invention is animprovemerit. the blanket. transferring the. impression from the printing plate onto the web; stock. which is suitably heldv against thev blanket by a third cylinder known. as an impressioncylinden An object of the invention. isto provide means for attaching. the blanket. tothe transfer cylinder and for taking up any stretch of the blanket which necessitates; only a relatively small longitudinal. opening in thetransfer cylinder so. that. the maximum of actual printing surface is secured, frorna cylinder ofsmall diametein.

A further objectv of the invention. relates to the provision of means for easily and securely attaching one end. or the blanket tothe transfer cylinder, this meansin the illustrated ernbodimentofi the invention being adjustable to take up any stretch which may takoplace in. the blanket over. aperiod of. time. Forthis' purpose the transfer cylinder, is provided with a narrow longitudinal groove into which one of a set. of; clamping. barsv is seated. Each clamping, bar is; provided with tapped. holes, the holes; in the different. bars of the setbeing. arranged atdifierentdistances from the, edge of. the bar. One end of the blanketis. provided witha. series. of holes through whicha plurality of securing screws pass into said tapped holes so. that: the; end; or the. blanket may beheld in. any: one; of. a. plurality of: positions depending;

upon which bar is. used... An alternative: means.

for taking up. the stretch of: the blanket. is: provided' in: connection withv the:- bar' secured to; the. end thereof. When the blanketaisanewi. the ed e" of thislbarmay be seated directly against: a-.wa1lofthegroove. inthecylinden; When the; blanket has; stretched, it is: aieatureor, the-invention; that adjustable. means is associated with the: bar for taking. up such stretch. For this. purpose; the;

opposite. ends of. the bar are, provided with two shallow notches; adapted; to: receive thin proiectingdugs formed: atztheend'sof a. thin metal shim. whichis interposed between the edgeoi the bar and: the wall of; the: groove. By; providingsets or shimsof different: thicknesses, any stretch. of. the.

blanket which occurs. during: its useful life may be readily'taken up.

, A further feature of the invention relates to. the provision of a. novelforrn. of securingmeans for securing; the opposite end. or blanket. to; the transfer cylinder: andfor: tensiom'ng; the blanket to the. proper degree so thatit. conforms closely to the cylindrical peripheral surface ct sucl'r cylinder. In the illustrated form of the invention;

. the end of the blanket. is clamped between. two

elongated bars which become seatedzirr the: longitudinal slot, in the transfer cylinder, one or these bars having its oppositev ends; provided: with; projecting; pins: which; extend into a. pair of. eccentric slots provided in a pair of. adjustable. collars mounted on. the. transfer" cylinder shaft. By rotatably adjusting these collar's;. the blanket clamping bars may be: drawn inwardly thereby drawing: the blanket" snugly againsirthe suriaceof the transfer cylinderand; also adjusting its ten.- sion to. any desired. degree.

Further objects of theinvention will become apparent as the. description: thereof proceeds. For a. better; understanding of the invention. reference' is. made to the following. descriptiontaken in connectionlwith' the accompanying drawing in. which:

Fig. l is a transverse sectional view of: a-transe fer cylinder embodying theoinventio'n with the blanket; in operative position thereon, a portion ofan. impression. cylinder bearing against the: trans-- fer cylinder also being shown;

Fig. 2: is-a transversewsectional view of the transfer cylinder shown in 1 with one: enct or the, blanket anchored imposition andthe other: end ready-to be inserted; into; the cylinder;

Fig; 3, is: a fragmentary side viewpartlyin section. ofqthe; transfer cylinder shown in Figs. 1; and) 2, the supporting means for the cylinder also being shown;

Fig. 4 is-a fragmentary view showing a portion of one end of the blanketand themeans for ad-- justably attaching such. end to the; transfer cyl.-- inder, including one or the clamping bars and a; shim; and

Figs. 5 and 6 are fragmentary views of other clamping bars showing different locations. of the tapped holes. i

The invention is illustrated in connection with a metallic transfer cylinder l, secured-1110a shaft 2 which is journaled at 3 for rotation in the; ad.- justable eccentric bearing; members B. of; the printing or .lithograph press. A pair. of cylindrical. gauge rollers it are. alsotsecured to. shatt 2,. he erollers serving topermit the. position of the manner described in the above mentioned Smith patent. A pair of collars 6 are mounted for rotation on the shaft 3, each collar being provided with an eccentric groove 1 having a radial opening 8 (Fig. l) 'andone .or more peripheral bores 9 adaptedto receive a pin of a spanner wrench (not shown). The purpose of the collars 6 will be referred to later.

The cylinder I is provided throughoutits entire length with a narrow longitudinally extending deep groove III adapted to receivethe ends of a thin rubber transfer blanket II- together with means for securing the ends of the blanket firmly in position. The illustrated means for securing one end of the blanket comprises an elongated metallic bar I2 adapted to be disposed in an exagainst the inclined wall I I of the slot I3. The other end of the blanket after being clamped between the bars 24 and 25 by the screws 21 is tension I3 of the groove III, the upper downwardly facing marginal wall M of extension I3 being inclined upwardly away from the groove proper, as shown in Figs. 1 and 2. .The upper edge I5 of the bar I2 is similarly inclined to seat against the inclined wall I4 and as a. result of such cam contact to be held against movement toward the groove proper, and the right hand face of the bar then wrapped around the cylinder I. This end of the blanket, together with the bars 24 and 25 are inserted in the manner shown in Fig. 2 into the groove I and moved radially inwards, the 'pins 29 entering the radial openings 8 and becoming seated in the eccentric grooves I. The blanket is then drawn into firm contact with the surface of cylinder I by rotating the collars 6 in an obvious manner with a spanner wrench, whereupon the pins 29 and bar 25 are forced radially inwards until the blanket is placed under the desired degree of tension. The stretch of the blanket due to its repeated or prolonged use may be taken up by removing the ends of the blanket and their fastenings from the slot I0, removing the screws 23 from the threaded holes I 9 and reinserting them through appropriate holes in the blanket into the threaded holes 21] located farther from the top of another bar I2. The blanket is then reassembled on the cylinder in the manner is provided at each end thereof with a shallow undercut or groove I adaptedto receive a lug I! provided on each end of and projecting from a metal shim I8 adapted to be interposed between the marginal wall I4 and the upper edgel5 of bar I2. The lugs I! serve to hold'the shim I8 in position while the bar I2 is being placed in position in the cylinder, shims I8 of variousthicknesses providing a means for taking up any stretch of the blanket I I in a manner hereinafter described. Without lugs I I, the shims would tend to slide off the upper inclined edge of the bar I2.

Another means for taking up any stretch of the blanket comprises the provision 'ofa pluralityof bars I2, 3 being illustrated (Figs. 4, 5 and 6) each having a series of tapped holes I9, or 2| formed in the bar, the holes in each series being alignment with each other, but with the holes 20 disposed at a greater distance from the edge of the bar than the holes I9, and the holes 2| at a still greater distance. The end of the blanket I I isprovided with a series of aligned holes 22 adapted'to receive a plurality of securing screws 23 in the respective bar I2 that is used.

The opposite end of blanket I I is clamped between a narrow bar "24 and a'substantially wider bar 25, the bar 24. being provided with a series of threaded holes 25 adapted to receive the screws 21 which pass through openings in the blanket I I and bar '25. The bars'Q24 and 25 and screws 2! constitute a barmeans with the bars 24 and 25 being portions thereof. As shown inFi gs'. 1 and 2',"th'e outer portion or part 28 of bar 25 is of somewhat greater thickness than its-inner portion or part and bears against both the inturnedf II when the baris in oper- Each end of ends of-the blanket ative position, as shown in Fig. 1. bar 25 is provided with a projecting pin 29 which extends into one of the eccentric grooves 1.

Inusing the device one end of the blanket is" attached to" the bar l 2 by inserting the screws 23 through. the holes 22 of the blanket into the series of holes I9 in the bar having holes closest to the top of the bar. The end of the blanket, together with the bar I I 0 into substantially the position shown in Figs. 1 and 2; so that the upper edge'of the'bar bears which-are threaded into either series of holes I9, 20 or 2| 2 arethen passed into the slot' above described. Any further stretch of the blanket may be taken up by repeating the above process and securing the end of the blanket to another bar I2 by threading the screws 23 into the series of holes 2|. Any further stretch of the blanket may be taken up by inserting a suitable shimIB between the upper edge I5 of bar I2 and the inclined wall I4 in an obvious manner. By using shims I8 of difierent thicknesses it will be clear that'any amount of stretch of the blanket may be readily taken up. Alternatively the stretch may be taken up without removing the .screws 23 from the series of holes in a bar I2 by inserting shims of suitable thickness between the inclined Wall I4 and the upper edge I5 of the bar. By using shims having a thickness less than the distance between the series of holes I9 and 29, any small amount of stretch may be readily taken up. Whichever stretch takeup means is used at one end of the blanket, the other end thereof is forced inwardly by the bar 25 and the collars 6 with their eccentric grooves I which draw the blanket into firm engagement with the surface of the cylinder I and place it under the desired tension. Fig; 1 shows theaforedescribed parts in their operative position with the blanket I I tensioned and disposed in rolling contact with the impression cylinder 5.

I havedescribed what I believe to be the best embodiments of my invention. I do not wish. however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim: p

In a press cylinder having a narrow deep longitudinal groove therein, the combination with a printing element formed of flexible material, a bar secured to one end of said printing element and arranged to engage a downwardly facing wall of the groove to anchorsaid end of the printing element in said groove, means for anchoring the other end of the printing element in said groove and means comprising a thin shim disposed between said wall of the groove and the bar to compensate for stretch of the printing element.

2. The'combination as claimed'in claim 1 in which said shimis provided with lugs disposed at an angle to the main bodyportion thereof, said lugs being adapted to engage the bar and thereed into position in the longitudinal groove. 7

3. The combination as claimed in claim 1 in which the bar is provided near its ends with a pair of shallow grooves and the shim is provided with lugs adapted to be seated in said shallow grooves.

4. In a press cylinder having a narrow deep longitudinal groove therein, the combination with a printing element formed of flexible material and provided along one end thereof with a series of holes, a plurality of elongated bars each adapted to be anchored in said groove and provided with a set of openings, the openings of the different sets being disposed at different distances from an edge of each bar, a plurality of securing members adapted to pass through certain of the holes in the printing element and into the set of openings in any bar, and adjustable means for forcing the other end of the printing element inward- 1y of said groove to thereby draw the printin element into firm engagement with the surface of the press cylinder.

5. The combination as claimed in claim 4 in which the openings in each bar are screw-threaded and the securing members consist of screws adapted for engagement with said screw-threaded openings.

6. The combination as claimed in claim 4 in which a thin shim is seated between the marginal wall of the groove and an edge of said bar, the thickness of said shim being less than the spacing between any two sets of said openings in different bars.

'7. The combination of a press cylinder having a narrow deep longitudinal main groove with parallel walls and a longitudinal secondary groove in one of said Walls, of a flexible printing element provided near one end with a series of holes, an elongated bar anchored in said secondary longitudinal groove and having openings therein including a set arranged in a 1ine spaced from an edge of said bar a distance corresponding generally to the length of said printing element as attached thereto, a plurality of securing members passed through certain of the holes in said printing element and into the openings in said line of said bar, a shim placed between the upper edge of said bar and the downwardly facing upper wall of the second longitudinal groove to provide a close adjustment of said printing element, and means for anchoring the other end of said printing element in said main groove.

8. In combination, a press cylinder having a narrow, deep, longitudinal groove therein with parallel .walls thereof fixedly spaced from each other, a printing element formed of flexible material, means for anchoring one end of said printing element in said groove, a pair of elongated rigid members, one of which being wider than the other and both being adapted to be fitted into said slot, means for clamping the other end of said printing element between said rigid members, the narrow rigid member bearing against the inner face of the inturned end of the printing element and the wider rigid member bearing against the outer face of the printing element, said wider rigid member, when said members are in the slot extending outwardly beyond the outer edge of the narrow rigid member and providing a part thereof of somewhat greater thickness than the part thereof adjacent the narrow rigid member whereby upon the rigid members being forced inwardly of said groove, the inturned end adjacent the outer part of the wider rigid member wil1 be forced over the outer edge of the narrow member and against a parallel wall of the slot thereby to conceal the narrow rigid member within the groove, filling the space between the Walls of the slot and preventing thereby the inflow of dirt thereinto, and means for securing the rigid members within the cylinder groove.

9. In combination, a press cylinder having therein a narrow deep longitudinal groove with the walls thereof fixedly spaced from each other, a printing element formed of flexible material, means for anchoring one end of said printing ele.. ment in said groove, bar means for anchoring the other end of said printing element in said groove comprising portions abutting both the inner and outer faces of said printing element at such other end thereof, the said outer face portion of the bar means extending depthwise of the groove to a greater distance than the inner face portion and adapted to extend outwardly beyond the outer edge of the bar means inner side portion when the bar means is located in the slot, the part of the outer face portion of the bar means extending beyond the outer edge of the inner face portion of the bar means being thicker than that part of the outer face portion immediately adjacent the inner face portion thereof thereby causing the inturned end of the printing element to be forced over the upper edge of the inner face portion of the bar means, wherebyto conceal the latter portion from the outside of the groove and to fill the space within the groove and prevent the inflow of dirt thereinto and means for securing the bar means within the groove.

LASZLO M. STEMPE'L. 

